Re: Postgres upgrade 12 - issues with OIDs

On Wed, May 5, 2021 at 07:49:29AM +1000, Venkata B Nagothi wrote:
> Hi There,
>
> We are attempting to upgrade our Postgres databases from 9.5 to 12.5 using
> pg_upgrade link mode and are facing issues with OIDs.
>
> ALTER TABLE... SET WITHOUT OIDs on the larger tables is taking very long and is
> locking up the table as well. We do have tables of more than 1 TB of size. 
> Is there any way to make this complete faster ?  Any suggestions would be
> great. 

Uh, I see this on our code:

pg_fatal("Your installation contains tables declared WITH OIDS, which is not\n"
"supported anymore. Consider removing the oid column using\n"
" ALTER TABLE ... SET WITHOUT OIDS;\n"
"A list of tables with the problem is in the file:\n"
" %s\n\n", output_path);

Uh, I don't know of any way to speed that up, though it might be faster
if it was done while no one else was accessing the table. I see this
comment in our PG 11 code:

/*
* If we dropped the OID column, must adjust pg_class.relhasoids and tell
* Phase 3 to physically get rid of the column. We formerly left the
* column in place physically, but this caused subtle problems. See
* http://archives.postgresql.org/pgsql-hackers/2009-02/msg00363.php
*/

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